Seafloor methane emission on the Makran continental margin.

Seafloor methane emission is widespread on both active and passive continental margins, which may exerts significant impact on global climate change, ocean acidification, cold seep ecosystem, and global carbon cycle. However, due to the limitation of the thick water body, systematic knowledge of detection, quantification and activity of the submarine methane seepage is still unreachable, which greatly limits the assessment of the environmental impact. In 2018, a comprehensive geological survey, including multibeam mapping, seafloor observation, and seismic reflection profiling, was conducted using R/V "Haiyangdizhi 10" on the Makran continental margin.

[The enrichment characteristic and mechanism of gold-silver minerals in submarine hydrothermal sulfides from the ultra-slow-spreading SWIR].

In the present study, content and occurrence of Au, Ag in three submarine hydrothermal sulfide samples from the ultra-slow-spreading Southwest Indian Ridge (SWIR) were studied by using inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of ICP-AES show that all of the samples have signs of Au-Ag enrichment. By SEM/EDS, we discovered a mass of gold-silver minerals in the samples.